Yes, teeth whitening pens are generally a safe option. Each of the brands listed and described above is formulated to minimize tooth sensitivity, and many of them use the same type of whitening agents that are safe for enamel and used in dental offices.
But if you’re concerned about the safety of a particular brand of teeth whitening pens, it wouldn’t be a bad idea to discuss these concerns with your dentist. In addition, suppose you have a history of tooth sensitivity. In that case, you should also talk to a dentist to see if using teeth whitening pens is a good option for you.